


The Irony of Life

by Kaggyin23



Category: Fate/stay night & Related Fandoms, Fate/stay night (Visual Novel), Fate/stay night - All Media Types
Genre: Erotica, F/M, Pegging, Romance, Sex, Smut
Language: English
Status: Completed
Published: 2020-10-15
Updated: 2020-10-15
Packaged: 2021-03-08 22:08:25
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,917
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27024043
Author URL: https://archiveofourown.org/users/Kaggyin23/pseuds/Kaggyin23
Summary: [One-Shot] Following the 4th Holy Grail war, the mages association was alerted by Kiritsugu of the true nature of the grail. After a delegation is sent to investigate, the greater grail is destroyed for good and the grail wars meet their end. Many years later, a 20 year old Rin Tohsaka is in need of an heir, and struggling to find the right man to give her one. [Rin/Kirei] [Smut]
Relationships: Kotomine Kirei & Tohsaka Rin, Kotomine Kirei/Tohsaka Rin
Kudos: 16





	The Irony of Life

…

*Beep*

…

Rin slowly but steadily opened her eyes as she heard a very annoying beeping sound. The girl then got up and turned the device off, still a bit disorientated.

The black haired young woman then went about her morning routine, taking care of her hair and dressing up for the day. All without that much drive, today was the day Rin had to make an important decision, and with her already not being good with waking up in mornings, she was really close to just going back to bed and spending her whole day curled up in there. The fact that the weather was extremely cloudy didn't help either.

As she sat down to eat a toast for breakfast, drinking a cup of tea, really taking her time. Rin started to reflect on her life up to that point.

Ever since her father died, the burden of carrying the Tohsaka family's legacy had been cast upon her. When younger, Rin wanted nothing more than to prove herself as a powerful magus, but after years of diligent studying and training, Rin was starting to understand the harsh reality that every mage went through at some point in their career.

She felt like she was approaching the limit of her capabilities. While not yet there, Rin realized that one day, she'd reach the pinnacle of her potential, and her growth as a magus would be stunted.

The solution to that lied in the magic crest system on itself. The mage would pass on his crest to an heir, and that heir would then add his own contributions to that crest, and then pass it on again. This had been the reality of bloodlines like the Tohsaka for a very long time.

And now, as she grew more mature, she knew that if she wanted all the magic knowledge her father and countless ancestors had amassed to not be lost forever, she'd need an heir, preferably one as capable or maybe more than herself.

The problem is that Rin was single, she'd never had any interest in romantic relationships, and the result of that is that she didn't even have any possible suitors for marriage. Not that she was interested in marriage, she could very well attempt an arranged marriage with another distinguished bloodline, she just wasn't interested in it.

She wanted someone that was a capable mage, and also willing to give her an heir with strong magic circuits and yet leave her to her own devices. Rin didn't want a husband nagging her all the time, she didn't need one.

When she thought about all those characteristics, one man came to mind: her father's disciple and her former legal guardian and teacher: Kirei Kotomine.

Kirei had been a bright disciple of her own father, she'd often hear her dad praising his skill and talent. He also trained her, and was one of the reasons as to why she became the person she is now. She also knew that he wouldn't interfere with her raising the kid the way she saw fit, and wouldn't bother her with any pointless couple stuff.

But that didn't change the fact that Rin was absolutely repulsed by Kirei.

Ever since she was a child, she just couldn't get along with the fake priest. And the mere fact that she had been considering asking him to give her a child had Rin wondering if she hadn't gone insane after all those years studying magic. But still, even if her heart was vehemently opposed to the idea, her mind was in favor of it. It made complete sense, and it would kill many birds with a single stone. And Rin had always been a person to put logic above feelings, or at least she thought so.

She had been considering this for months, and had set that day as the final deadline to make that decision. The young woman thought long and hard about different solutions but couldn't think of anything better. As much as she hated the idea, she'd have to go with it.

She'd have a child with Kirei Kotomine.

Finishing her meal, Rin made her way to the telephone and dialed Kirei's number.

"Kirei?" The girl asked, as she heard him pick up the phone.

"Oh, Rin?" The priest replied, a hint of surprise in his voice.

"We need to talk, it's something very serious." Said her, going straight to the point. "Are you free?"

"Indeed, i am." Kirei replied, in that usual unsettling tone of voice. "But if it's something of such serious nature, wouldn't you rather discuss it over a meal? I know a very good place…"

"No Kirei, i'm going there right now." Rin interrupted him, knowing full well he wanted to take her to that chinese restaurant he liked so much. She really didn't wish to spend more time in his company than necessary. "I'll be seeing you." She then hung up the phone.

Without wasting any time and preparing herself mentally to tell Kirei about her plans, Rin made her way to the Kotomine church through the streets of Fuyuki. It looked like it was gonna rain so she took a red umbrella alongside her.

Reaching the place, there he was: Kirei Kotomine, standing in front of the altar, waiting for her with that same smug grin in his face Rin still hadn't gotten used to.

"Good morning, Rin." Said Kirei, a bit amused. "It was quite surprising to me when you called earlier. After all, you completely cut contact with me after reaching adulthood."

"I was too busy." Rin lied, not wanting to prolong the conversation more than needed. "But that doesn't matter now." Rin took a few steps towards him. "Kirei, i'm here to make you a proposition."

Kirei raised an eyebrow, intrigued.

"And what would that proposition be?" He asked.

"For years, you've been an asset to the Tohsaka family. Your contributions in aiding my father and teaching me are undeniable." Rin spoke, sounding dignified. "And now, i'd like to offer you complete freedom from all your duties towards me and my family, if you only help me with one last thing."

Kirei smirked. He didn't have any duty that bound him to the Tohsaka family. It's true that he'd raised and trained Rin, but he also killed her father unbeknownst to her. And now, with her being an adult and him no longer being her guardian, he essentially didn't have anything to do with the Tohsaka anymore. She was obviously trying to rope him into something.

He also knew that she had no affection for him and most likely just wanted to use him. Still, he was intrigued, and decided to listen to what she had to say.

"Very well, what is it?" He asked.

"I…" She had a bit of trouble saying it. "I need you to give me an heir, Kirei."

It had been many years since the priest had been so surprised, although he didn't show it on the outside. Did that really just happen?

"I'm sorry, Rin. I'm afraid i didn't quite catch that." Said Kirei, with a smirk, wanting to hear her say it again.

"I said i need you to give me a child." Rin answered. "One day i'll pass the Tohsaka family's magic crest into a worthy heir, and i've decided that you're the best suited person to give me one."

Kirei chuckled. Rin Tohsaka, the daughter of Tokiomi Tohsaka, who Kirei had betrayed and murdered, wanted to have his kid.

It was these types of things that made Kirei's life worth living in his eyes. He couldn't help but feel excited at the amount of possibilities for enjoyment that could arise from that. The sheer discomfort that Rin had been emanating from that conversation alone had been enough to make his day.

The fake priest then started to walk in circles around the girl, who stood in the middle of the church.

"Don't you think that's a bit inappropriate?" Asked the priest, still with a smirk, to make her even more uncomfortable. "I was your legal guardian for a long time, i raised you, and taught you everything you know. What would your father think?"

He was starting to get on her nerves. Like he always does.

"I'm not a child anymore." Rin answered, clearly annoyed by him. "And my father would want the Tohsaka bloodline to be preserved, and the best way of achieving that is for me to have your child, i'm sure he'd support my decision."

Kirei however, hadn't given up.

"But why me? I'm sure a talented magus from a distinguished family such as you wouldn't have trouble finding suitors." He insisted, still walking circles around her.

Rin gripped her fists, doing her best to remain composed.

"I'm not interested in getting married." She answered, going straight to the point. "I just need someone who can give me a capable heir to raise as i see fit. After i confirm my pregnancy, i'll relieve you of all your duties to my family and we'll probably never see each other again. You'll have no part on the child's upbringing and will stay away from us."

Kirei then stopped in front of the altar, and turned himself to Rin's direction. Looking at her in the eyes, analyzing her.

"Very well then." Kirei opened up a smug smile. "I accept." The fact that he not only would bed the daughter of man the betrayed and murdered, but impregnate her with his seed, making him the father of the new heir of the Tohsaka family, was something he'd derive incredible joy from doing.

Kirei wasn't physically attracted to Rin, nor did he have any romantic feelings for her at all. But to do what would be like pissing in Tokiomi's grave, it would be to taint his legacy and his memory forever. For a man as evil as Kirei Kotomine, that prospect was enough for him to accept, even though there was more.

Rin felt shivers through her body as she heard him say that, but once again, tried not to display any emotion at it.

"Come to my house tonight at eight." Rin said, as she turned her back on him.

"I'll see you there." He said, as he saw the black haired girl leave the church.

-x-

It was already eight, and Rin waited patiently in her living room for Kirei to arrive. The girl, in her nightgown, sipped some tea as she listened to the rain outside.

A few seconds later, her doorbell rang, and Rin got up to answer the door. As she opened it, there was Kirei Kotomine, holding a black umbrella and wearing his traditional smug facial expression.

"Good evening, Rin." He greeted, as he entered the Tohsaka residence. "Well, i'm here."

Rin took a deep breath as she truly dreaded what was about to happen in a few moments.

"Wait here, i'll go prepare myself in my room and i'll tell you when to come in." She explained, as she closed the door and started to climb the stairs that led to her bedroom.

Already there, Rin looked at herself in the mirror as she slowly took off her nightgown and then panties. She really was about to do it, she was gonna have sex with the man who raised her, she was gonna have sex with Kirei of all the poeple in the world.

It took a few seconds of her staring at her naked body in the mirror for her to gather all of her courage. Finally feeling ready, the girl went back and left the door half opened.

"Kirei, you can come in."

As the priest climbed the stairs and entered the room, he was met by the vision of Rin, completely naked, lying back on her bed. She was doing her best to hide her embarrassment but Kirei knew her too well, that on it's own already made him a bit excited.

"Stop staring and take off your clothes already." Rin said, in a bossy tone.

And as the fake priest removed his garbs, and made his bulky and muscular naked body visible to the girl, Rin started to check him out a bit. She hated Kirei, but it was impossible to deny the fact that he was hot. Looking at his defined muscles and the knowledge that he was about to have sex with her made Rin's pussy ache a little bit.

That aching only got stronger as Kirei climbed into the bed and Rin noticed his big and hard cock, that thing was going inside her that night, she thought. She even got a little nervous as she imagined what it would feel like inside.

"Rin, please spread your legs." Kirei asked, snapping her out of her daydreaming. "If you don't, i won't be able to get through."

"I know, you don't have to tell me that…" Rin then slowly spread her legs open, revealing her pussy, still not very well lubricated, to the man who had raised.

Kirei then smirked and got closer, like a tiger preparing to strike against its prey. He grabbed Rin's arms and got on top of her, pressing the tip of his hard cock against her entrance.

"Wait, i'm still not wet enough." Rin said, a bit concerned.

"Oh? I was under the impression that this was strictly for procreation." Kirei smirked as he said that. "But if pleasure is what you truly seek, you need only to tell me."

Rin's face got red, she hated when he treated her like that.

"Forget it." Rin said, feeling his breath on her neck and shoulders. "Let's just get this over with."

Hearing that, Kirei penetrated her with full force, thrusting his entire length inside her in one go, sending massive jolts of pure pain through Rin's body.

"Ahhhhhhh!" The girl yelled, as the fake priest kept ramming it inside her, no regards at all for what she was feeling.

The fact that Rin's pussy hadn't been properly lubricated before the penetration, and the fact that Kirei's cock was really big, made it so that she didn't feel any pleasure at all doing it with him. It was all pain, jolts and jolts of pain as Kirei fucked her like an animal, with Rin screaming very loudly.

Kirei, however, was deriving an incredible amount of pleasure from the sex, not for the act itself, but for the suffering that Rin was enduring as he reshaped her tight pussy, he fucked her with all his might, delighted at her screams. Soon, the climax of pleasure was upon Kirei, and he released rope after rope of his seed deep inside Rin's womb. As she felt his hot cum fill her insides, Rin stopped screaming, slowly getting used to the pain.

Satisfied, Kirei took out his cock, as he watched his cum drip a bit from her pussy entrance. Rin was still in the bed, panting, still feeling some leftover pain from the sex.

That rough sex really hadn't been pleasurable for the girl, but towards the end she did feel a bit of pleasure, but she hadn't achieved orgasm him. And that feeling was something that really irked her. She wanted to orgasm, even though her pussy had already been filled.

"Kirei…" She said, still panting a bit. "Keep going."

The priest smirked.

"But i've already provided you with my seed. What would be the point for me to keep going?" He asked.

Rin wanted to cum, she wasn't in the mood to play his games.

"Just shut up and do it, you bastard!" She spread her legs again as she looked at his eyes, defiant, inviting him to keep going. Her pussy had been lubed by his cum, this time it would be easier for her to cum as well.

And so, he went at it again. Kirei pressed his cock against her pussy, but this time it went inside easily. And so, he started once again to rock his hips against hers. Rin's screams now were but moans of pleasure, as she enjoyed every inch of that big cock that filled her.

Rin grabbed his muscular back as she felt jolts of intense pleasure go through her body, then started to bounce her hips against his too, increasing the pleasure. She was horny, her nipples were hard and Kirei noticed all of it, relishing on that fact. Rin hated it, she despised Kirei, but couldn't deny that sex with him felt feally damn good.

As her orgasm finally came, Rin gripped Kirei's back with her legs and hugged him around the neck as her pussy started to contract and tighten up around the priest's shaft. Rin was coming, she was coming with Kirei's dick inside her, that sensation was one of the best she ever felt in her life. The sheer taboo and shame that she felt all translated into pure pleasure during that act.

Once again, Kirei removed his cock from inside her. And smirked as he saw her in that post orgasm bliss state. However, this time, he was the one who wasn't yet satisfied, as his cock was still hard and ready to go.

Rin then finally came back to her senses, sitting on the bed, unsure of what to think, say or do.

The only thing that she was sure of is that the sex felt really god damn good. And that she was a bit mad for him taking the lead and treating her like a child during the act.

The girl looked at the priest's muscles, slowly starting to get horny again, and then noticed his hard cock.

"So, you're still hard." She commented, as she looked at it.

"I'm afraid so." Kirei answered, intrigued. Was Rin already ready to go again?

After hearing his answer, the girl, out of nowhere, grabbed him, and did a bajiquan move on the priest, dropping him face first into the bed. She then grabbed Kirei's butt, got on top of him, and used a reinforcement spell on her right finger.

"You think you can play and do as you please with me?" Rin asked, in a venomous tone of voice. "I'm not a child anymore Kirei, i'm not that kid you used to teach magic to anymore." She grabbed his cock with her left hand. "I'm a full fledged magus of the Tohsaka family, i'm the one who's in charge, and i'll prove it to you. Take this as payback for all these years, i'll make you feel the same as i felt."

Kirei was stunned, he really did not expect what had just happened. But before he could think, Rin started to stroke his cock with her left hand, and to penetrate his asshole with her right finger.

Kirei moaned as Rin pegged his ass with her reinforced finger, each thrust that Rin did made Kirei's cock harder, and it didn't help that the girl was stroking him at the same time. Kirei didn't understand why he was feeling pleasure out of that, Rin was dominating him, she was the one taking the lead and fucking him, why was that so pleasurable? He didn't have the answer as of now.

Rin was incredibly wet. All those years she had hated Kirei, all those years she had felt this complicated mixture of negative and a few positive feelings towards the fake priest. And yet she'd never been able to act on them like this. Catharsis didn't even begin to define what she was feeling right then. Her boobs bounced with her hard nipples as she fucked the man who'd raised her and made him moan like a little bitch.

Eventually, Kirei would cum, and send rope after rope of spunk into the bed sheets. Rin then released him and watched as the fake priest fell face first into the bed, panting just as she was.

"Now we're even." She said, panting herself, feeling a bit out of breath.

Kirei was smiling in an evil bliss, he imagined what Tokiomi Tohsaka would think if he'd seen what had just happened. The priest turned around, laying on his back, as he watched Rin's naked form in her knees on the bed.

He had never found her particularly attractive, but now, for some reason, he was starting to. Maybe it was just hormones, but he thought that Rin's slender figure, the complexion of her skin, her round but average breasts and her silky black hair were strangely beautiful.

Rin was on the same boat, she just couldn't take her eyes off Kirei's abs. Maybe that was all hormones and reproductive instincts, but she couldn't wait to have another go at him.

Soon, their gazes met with one another, and no words needed to be said. Rin crawled atop him, grabbed his cock with her hand, and impaled herself with it, sitting on his already hard again cock. Rin was drowning with pleasure as she slowly started to ride Kirei's cock at her own volition. She started to ride him like a stallion, rocking her hips against him and desperate to feel more of his hot seed fill her completely.

She moaned loudly, without a care in the world as he grabbed her ass cheeks as she bounced her hips and rode him harder and harder, he started to slap her butt, making her moan even more, which in turn caused her to start slapping him in the face.

Kirei then grabbed her breasts, and started to thrust his own hips against hers too, he brought her down, closer to him, as he sucked and passed his tongue through her right nipple. Rin moaned like crazy, feeling pleasure like never before in her life.

Eventually, Rin reached her climax, her pussy tightening and contracting like crazy against his hard cock. Which in turn caused Kirei to cum as well, once again filling her womb with rope after rope of his hot seed.

And as the post orgasm bliss slowly took ahold of their minds, they both fell asleep, exhausted, after all that sex.

…

Next morning, Rin found herself waking up alone in bed. But once she looked to the other side of the room, there was Kirei, naked, sitting on a chair next to the window.

"Good morning, Rin." He said, still smug.

Rin was feeling a little embarrassed, she remembered everything that had happened last night, and yet she didn't regret it. It felt incredibly good, amazingly good. Even now as she still felt his seed inside her womb, it gave her a warm feeling of comfort. She had hated Kirei for her entire life, but after that night, she felt like she understood him a little bit better, was her hatred for him diminishing? It was still too early to tell.

"Hey, Kirei." She got a bit embarrassed as she started to talk.

"What is it?" He asked.

"I think you should help me teach my child, i mean, you've proven yourself to be a capable teacher." She said, looking away. "I think it'll be… good, to have you around."

Kirei smirked, knowing full well the true meaning behind her words.

"I'll consider it." He answered, standing up. "Should i come back tomorrow for us to continue trying for the baby?"

Rin waited a few instants before answering.

"I think it's better if you just stay here for the time being, to save you the trouble of coming back and forth from here to the church…"


End file.
